Same issue here - where we can push new stages into Google Ads, but the data is not flowing. If I get a support solution I'll update this post. My theory is that all of the stages need to be mapped into Google Ads, and not just select stages.
Edit: our issue may have been different from your own - our data is flowing after confirmation from Marketo Support, but we received continual AdWords errors with 'invalid user'. This is because if you have multiple Google Ads accounts, you need to create a MCC - a GCLID on a record can already be attributed to a user not authorized in the account you linked to the Marketo integration.
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